In general, liquid crystal panels for liquid crystal displays, which are one example of displays, are provided with a TFT array substrate that includes thin-film transistors (i.e., TFTs) or pixel electrodes connected to TFTs. A display area is formed by arranging such TFTs and pixel electrodes in a matrix. The TFT array substrate includes scanning signal lines connected to the TFTs, and display signal lines connected to the TFTs.
Such a TFT array substrate has a single element section that includes a plurality of scanning signal lines and display signal lines. Terminals for inputting signals to the scanning signal lines and the display signal lines are provided at the edge of the element section of the TFT array substrate.
A color filter (i.e., CF) substrate is further disposed as a counter substrate to the TFT array substrate. The color filter substrate includes, for example, a counter electrode and a resin film.
The TFT array substrate and the color filter substrate are bonded together with a seal member. Here, the seal member is formed in a frame shape to surround the display area. A liquid crystal is further sealed in the area formed by the TFT array substrate, the color filter substrate, and the seal member. Then, devices such as a driving IC and a flexible printed circuit board (i.e., FPC) are mounted, and furthermore devices such as a backlight unit are mounted, whereby a liquid crystal display module is completed.
When there is a foreign substance in an area on the outside of and adjacent to the space in which the liquid crystal is sealed, an insulation film that is formed to cover terminal lines may be damaged by the foreign substance. If this is the case, flaws in the insulation film may reach and expose the terminal lines. This deteriorates the insulating properties of the terminal lines.
If, in this situation, moisture or the like adhering to the counter electrode on the color filter substrate enters the flaws in the insulation film, a conductive circuit may be formed between the counter electrode on the color filter substrate and the terminal lines on the TFT array substrate. In this case, problems such as disconnection due to electrolytic corrosion may occur.
The cause of the formation of the conductive circuit between the counter electrode and the terminal lines may be the entry of a metallic foreign substance (i.e., conductor foreign substance), instead of moisture, from the flaws in the insulation film.
To address this problem, structures are disclosed in which the terminal lines on the TFT array substrate are covered with a protective film or the like (see, for example, Patent Document 1). Other structures are also disclosed in which a hydrophobic film or a resin film is formed on the counter electrode of the color filter substrate (see, for example, Patent Documents 2 and 3).